function extractNumber(obj, decimalPlaces, allowSlash) {
	var temp = obj.value;
	
		var reg0Str = '[0-9]*';
		if (decimalPlaces > 0) {
			reg0Str += '\\.?[0-9]{0,' + decimalPlaces + '}';
		}
		
		else if (decimalPlaces < 0) {
			reg0Str += '\\.?[0-9]*';
		}
			reg0Str = allowSlash ? '^/?' + reg0Str : '^' + reg0Str;
			reg0Str = reg0Str + '$';
				var reg0 = new RegExp(reg0Str);
				if (reg0.test(temp)) return true;

				
				// do not allow notnumbers
			var reg1Str = '[^0-9' + (decimalPlaces != 0 ? '.' : '') + (allowSlash ? '/' : '') + ']';
			var reg1 = new RegExp(reg1Str, 'g');
			temp = temp.replace(reg1, '');
			
			if (allowSlash) {
			var hasSlash = temp.length > 0 && temp.charAt(0) == '/';
			var reg2 = /-/g;
			temp = temp.replace(reg2, '');
			if (hasSlash) temp = '/' + temp;
			}
			// for some cases we need decima places (amonut etc)
		if (decimalPlaces != 0) {
			var reg3 = /\./g;
			var reg3Array = reg3.exec(temp);
			
			if (reg3Array != null) {
			var reg3Right = temp.substring(reg3Array.index + reg3Array[0].length);
			reg3Right = reg3Right.replace(reg3, '');
			reg3Right = decimalPlaces > 0 ? reg3Right.substring(0, decimalPlaces) : reg3Right;
			temp = temp.substring(0,reg3Array.index) + '.' + reg3Right;
			}
		}
			obj.value = temp;
}

function blockNonNumbers(obj, e, allowDecimal, allowSlash)
{
	var key = null;
	var isCtrl = false;
	var keychar;
	var reg;
	
	if(window.event) {
		key = e.keyCode;
		isCtrl = window.event.ctrlKey;
	}
	
	else if(e.which) {
	key = e.which;
	isCtrl = e.ctrlKey;
	}
	if (isNaN(key)){ 
		return true;
	}
	
	keychar = String.fromCharCode(key);
	
	// check for backspace or delete, or if Ctrl was pressed
	if (key == 8 || isCtrl){
	return true;
	}
	
	reg = /\d/;
	var isFirstN = allowSlash ? keychar == '-' && obj.value.indexOf('/') == -1 : false;
	var isFirstD = allowDecimal ? keychar == '.' && obj.value.indexOf('.') == -1 : false;
	return isFirstN || isFirstD || reg.test(keychar);
	}


